About

Sesame is a Python3 package for solving the drift diffusion Poisson equations for multi-dimensional systems using finite differences.

The software computes the steady state of a semiconductor between two contacts, and subject to voltage bias and/or illumination. It was developed to study polycrystalline solar cells containing charged interfaces (grain boundaries, sample surface). Sesame handles single charged states and continuum of defect states alike.

Sesame includes modules that can be used in Python code as well as a standalone GUI (contained in app.py of the head directory of the distribution). Example scripts and GUI input files can be found in the examples directories. The documentation includes tutorials describing example scripts. Online documentation can be found here <http://sesame.readthedocs.io/en/latest/>_ .

Support for this project comes from the U.S. National Institute of Standards and Technology and the University of Maryland.

Installation instructions

Prerequisites ..............

Building Sesame requires

• Python <http://python.org>_ 3.4 or above,
• SciPy <http://scipy.org>_ 0.9 or newer,
• LAPACK <http://netlib.org/lapack/> and BLAS <http://netlib.org/blas/>, (other options are the free OpenBLAS <http://xianyi.github.com/OpenBLAS/> or the nonfree MKL <http://software.intel.com/en-us/intel-mkl>.)

The following software is highly recommended though not strictly required:

• Matplotlib <http://matplotlib.sourceforge.net/>_ 1.1 or newer, for Sesame's plotting routines. Matplotlib is required when using the graphical interface of Sesame.
• MUMPS <http://graal.ens-lyon.fr/MUMPS/>_, a sparse linear algebra library that will in many cases speed up Sesame several times and reduce the memory footprint. (Sesame uses only the sequential, single core version of MUMPS. The advantages due to MUMPS as used by Sesame are thus independent of the number of CPU cores of the machine on which Sesame runs.)
• An environment which allows to compile Python extensions written in C, C++ and Fortran.

The graphical user interface requires PyQt5 <https://riverbankcomputing.com/software/pyqt/intro>_.

For users with no python installation, a convenient standalone installation which automatically includes all of the requisiste libraries and packages is Anaconda <https://www.anaconda.com/>_ .

Generic instructions ..................... Standard build and install ++++++++++++++++++++++++++ Sesame can be built and installed following the usual Python conventions <http://docs.python.org/install/index.html>_ by running the following commands in the root directory of the Sesame distribution::

python setup.py build
python setup.py install

Depending on your system, you might have to run the second command with administrator privileges. The installation step can be done locally either by using the --user prefix::

python setup.py install --user

or by specifying the location where to install the package files with --prefix=/path/of/directory.

The tutorial examples can be found in the directory examples inside the root directory of the Sesame source distribution.

Building the documentation +++++++++++++++++++++++++++

To build the documentation, the Sphinx documentation generator <http://sphinx.pocoo.org/>_ is required (version 1.4 or newer) with numpydoc extension (version 0.5 or newer), and Latex.

HTML documentation is built by entering the doc sub-directory of the Sesame package and executing make html. Open the file index.html in the directory build/html with a web browser to access the documentation. PDF documentation is generated by executing make latex followed by make latexpdf. The pdf file is generated in build/latex.

Because of some quirks of how Sphinx works, it might be necessary to execute make clean between building HTML and PDF documentation. If this is not done, Sphinx may mistakenly use PNG files for PDF output or other problems may appear.

As an alternative if make is not available, the HTML documentation can be built using the command from the root directory::

python setup.py build_sphinx

The documentation is produced in doc/build/html. To build the PDF file::

python setup.py build_sphinx -b latex
cd doc/build/latex
make all-pdf

The resulting PDF is produced in doc/build/latex.